1. SO2   sulfur dioxide   calcium sulfate   ammonia   carbon disulfide   Hint Hint       2. KOH   ammonia   sodium carbonate   potassium permanganate   potassium hydroxide   Hint       3. MgO   ammonia   magnesium oxide   nitric acid   sodium carbonate   Hint       4. H2O   potassium permanganate   copper sulfate   water   sulfur dioxide   Hint       5. KMnO4   carbon disulfide   potassium permanganate   sodium hydroxide   sulfuric acid   Hint       6. CS2   carbon disulfide   potassium nitrate   sodium carbonate   ammonia   Hint       7. (NH4)2SO4   magnesium oxide   carbon dioxide   copper sulfate   ammonium sulfate   Hint